Method and apparatus for applying metal coatings



. March 8, "1938. P. A. BLEAKLEY 2,110,755

METHOD AND ARPARATUS FOR APPLYING METAL COATINGS Fi led Feb. 7, 1953 5 sheets-.s'heet 1' jNvENTOR o FURUNGA.BLAKLEY .ATT'oRNEY March'S, 1938. P.'A. BLEAKLEY w METHOD AND APPARATUS FOR APPLYING METAL COATINGS March 8, 1938. P. A. BLEAKLEY METHOD AND APPARATUS FOR APPLYING METAL COATiNGS Filed Feb. '7, 1933 5 Sheets-Sheet 5 INVENTOR .Y m. M E I- A 6 w m P AT'TO NEY Patented Mar. 8, 1 938 UNITED STATES mcrEN OFFICE METHOD AND APPARATUS FOR APPLYING METAL COATINGS Purling A. Bleakley, Hollywood, Calif., assignor,

by mesne assignments, to The Gillord Corporation, a corporation of Delaware This invention has to do in a general way with the art of surfacing articles or objects, such as the interior of cylindrical objects, and is more particularly related to a method and apparatus for applying a hard metal surface having a high co-efiicient of friction and. a consequent high gripping action to the wearing surface of articles such as brake drums or the like, although the contemplated by this invention, is obtained by spraying the wearing surface of the drums with hot metal in a manner such that the deposited coating comprises a porous mat which is formed of overlapping layers of metal particles bonded to each other and to the drum. By laying the sprayed metal onto the wearing surface in the overlapping manner just described, the surface formed can be ground so that the finished article is perfectly symmetrical and can be-used indefinitely without danger ofchipping or flaking.

It is a well known fact that metal, such as steel for example, when it is deposited by the so-called spray method is not only porous but is increased in hardness over the original -metal. Also in view of its more or less porous qualities it has a much higher co-eflicient of friction and gripping action than the. original metal. With this in mind, my invention also contemplatesas an article of manufacture, a brake drum, the wearing surface of which has a coating of the type just described: 4 g

It is one object of this invention to produce a method for applying a coating, of the type referred to above, to the interior of a brake drum or the like. This method consists in a general way of directing a metal spray against the wearing surface of the brake drum while rotating the brake drum and at the same time effecting relative movement, in a direction parallel to the axis of rotation of the drum, between the drum and the spray. t

The means for producing the metal spray may be any conventional type of so-called spray gun whereby a metal wire or rod is melted by means of an oxyacetylene flame or the like and the molten metal as it forms is torn from the rod, disseminated, and deposited on the surface being sprayed by means of a high velocity blast of compressed air. However, it is a primary object of this invention to produce a machine whereby a gun of the class described may be used to lay a uniformly matted coating which is made up of overlapping layers of the type referredto above.

It is a further object of this invention to produce a machine of the class described wherein a plurality of drums or other articles may be simultaneously coated in the manner referred to. In this connection, it is an important feature of the machine contemplated by this invention that surfaced drums maybe replaced with unsurfaeed drums during the surfacing of another set of drums.

The machine contemplated by this invention consists in a general way of a table which is rotatably supported 'upon suitable supporting means and is associated with a table clutch oper-- ated by a main drive shaft for the purpose of effecting intermittent rotation of the table at predetermined intervals. An upright guide member mounted upon a suitable support is situated adjacent the table and this-guide member car'- ries a traveling arm which has a projecting end situated above the table for supporting, in adjustable relation with respect to the table, one or more spray guns. The table is provided with a plurality of work supporting members which,

in the example given, will carry mandrels supporting the brake drums, and latch means are provided for engaging suitably positioned stops on the table to lock and hold the same against rotation in a position wherethe drums are exposed to the action of the spray.

Means are provided for rotating the drums from the main drive shaft at such times as the table is held stationary, and means in the form of an upright feed screw, associated with a traveling member, is provided for the purpose of moving the supporting arm and the spray gun downwardly toward the drums and upwardly away from the drums to apply the overlapping layers of matted metal to the interior surface of the rotating drums. The down and up move. ment of the traveling member on the feed screw,

which is driven from the main drive shaft, is

effected by means of a clutch mechanism on the main drive shaft and a trip mechanism actuated by the traveling member.

It is a further object of this invention to pro- I vide'a machine of the class described with a trip mechanism which is actuated to reverse the rotation of the feed screw when the arm reaches form the trip mechanism so that the feed screw clutch is thrown into neutral when the arm reaches its uppermost position and which at the same time includes a mechanism for releasing the table latch to permit the free rotation of the 'table and to engage the table clutch for efiecting such rotation while the 'feed screw clutch is held in neutral.

Another feature of this invention resides in the provision of a cam member associated with the stop means on the table and adapted to engage a lever member associated with the trip mechanism which will simultaneously disengage the table clutch, move the table latch into a. position in which it will engage a stop on the table, and reengage the screw clutch so-that immediately upon the table being locked into position the screw becomes operative to initiate the downward movement of-the spray gun relative to the next set of rotating drums.

It is a further object of this invention to em- .body in the trip mechanism, referred to above a reciprocable shifter rod, the upper end of which is received in a socket provided with valves and conduits so as to form a compact automatic oil pump for spraying lubricant upon the screw and its associated mechanism during all periods at which the machine is operated.

Another important feature in the machine contemplated by this invention, is that the table and its associated parts are so constructed as to balance the momentum of the driving mechanism. In other words, the main driving gear which engages the driving shaft is always engaged. The table clutch merely locks the table to a ring gear associated withthe main driving gear so that the momentum is either stored in the rotating table or in the drums (which, incidently, do not rotate during the movement of the table) and is consequently never lost or wasted.

It is a further object of this invention to produce a device of the class described which can be adjusted for operation on drums or objects of any desired width.

A still further object of the invention is to pro-' vide the machine with manually adjustable means for locking the screw clutch and the trip mechanism which actuates the table clutch in a neutral position.

The machine contemplated by this invention is entirely automatic in its operation, the only manual operations necessary being the replacement of the unsurfaced drums, which replacement can be effected simultaneously with the surfacing of another drum or set of drums.

The details in the construction of a preferred embodiment of my invention, together with other objects attending its production, will be best understood from the following description of the accompanying drawings which are chosen for'illustrative purposes only, and in which Fig. 1 is a perspective-view illustrating a preferred embodiment of my invention and showing the sameequipped with brake drums and with two spray guns in operating position;'

Fig. 2 is a fragmentary plan view partly broken away and showing the brake drums as having been removed;

which may be considered as having been taken in a plane represented by the line 3-3 in Fig 2.

and is shown with the table member having been rotated through substantially 45 in order to bring a drum supporting portion thereof in the section plane;

Fig. 4 is an elevational view which may be considered as having been taken in the direction of the arrow 4 in Fig. l and which shows the rear face of the machine contemplated by this invention;

Fig. 5 is a sectional elevation taken in a plane represented by the line' 5--5 in Fig. 4 illustrating the construction of the feed screw and its associated parts;

Fig. 6 is a fragmentary plan section taken in a plane represented by the broken line 66 in Fla 5;

Fig. 'I'is a fragmentary plan section taken in a plane represented by the line 11 in Fig. 5;

Fig. 8 is a fragmentary plan view taken in a plane represented by the line 8-8 in Fig. 5;

Fig. 9 is a fragmentary sectional elevationtaken in a plane represented by the line 9-9 in a.

Fig. 10 is a fragmentary elevation taken in a plane represented by the line I 0-! in Fig. 2 and illustrating the details in the construction of the table latch mechanism;

Fig. 11 is a sectional view taken in a plane represented by the line ll-ll in Fig. 10;

Fig. 12 is a sectional view taken in a plane represented by the line l2|2 in Fig. 10;

Figs. 13 to 16 inclusive are diagrammatic views illustrating the various steps in the operation of the latch mechanism, the trip mechanism, the table clutch, and the screw clutch;

Fig. 17 is a sectional view of a brake drum illustrating the manner of applying the sprayed metal; and

Fig. l8 is a fragmentary section illustrating the character 'of the metal coating.

More particularly describing the invention as herein illustrated, reference letter A indicates a base plate or a base member which carries a table support generally indicated by reference letter B, which in turn rotatably suppor'ts a table indicated at C. The table C is adapted to be intermittently rotated through a clutch and gear mechanism, which will hereinafter be more fully described, from a main drive shaft D. While the table is held in a stationary position, by means of a latch mechanism, generally indicated at E, the main drive shaft D is eifective to rotate a plurality of chucks F which carry spindles G upon which brake drums H are mounted.

The latch mechanism E is constructed and positioned so that it holds the table in a position where one or more of the drums H are .held in alignment with the nozzle portions of metal spray guns I and I which are mounted upon gun supporting brackets J and J. The brackets J and J are mounted on the end portions of an inverted T-head K which is in turn mounted for adjustment in a sleeve L formed on the end of a supporting arm M. The arm M has one end slidably mounted in a guide or way formed on the face of an upright housing 0 which contains tor Q. Fig. 3 is a fragmentary sectional elevation The metal spray guns I and 1' maybe of any conventional type, sufiice it to say at this time for the purpose of clearly describing the invenmember .II which is provided with a connectionv 12 for receiving a mixture of oxygen and acetylene delivered thereto through a suitable header indicated at l3 mounted on the housing 14 from hoses l5 and I5. Another conduit l6 which is connected through avalve in the housing (not shown) to another hose I1 is provided for delivering compressed air tothe nozzle.

Reference numeral l8 indicates a wire or rod which is fed into the nozzle II by a suitable feed and straightening mechanism contained within the housing l4, such wire or rod coming from a reel or other suitable source not shown.

As the wire I8 is fed into the nozzle H, it is melted by the oxyacetylene flame and is dissem-.

inated and deposited by the compressed air on the interior of the drum H which is being revolved through the drum revolving mechanism which will be described later.

The nozzle housing I4 is mounted upon a plate l9 which is adapted to be adjusted longitudinally of the nozzle supporting bracket J by means of a screw 20 and a hand wheel. When two guns are being used in the manner shown, it is preferable to adjust one gun for use on rear" drums,

and the other for front drums. Since the mountings for the front and rear drums are different, this permits the coating of a complete set of drums at one operation. I

The machine is constructed and operated so that the table C is rotated into a position at which two of the drums H are positioned below the two nozzles where it is latched by the latch mechanism E. The latching of the table is automatically efiective to initiate the downward movement of the supporting arm M. When the nozzles have reached a position at which they are spraying the lower edge of the wearing surface of the drums, the machine having been previously set for the proper drum width, the mechanism which operates the arm is automatically 5 reversed without disturbing the table and the arm is raised to its upper position at which the latch is automatically released to permit the rotation in alignment with the nozzles and the operation is repeated.

Referring now to the details in the construe-- tion of the table and its associated parts which are bestillustrated in Figs. 2 and 3, reference numeral 23 indicates an uprightspindle which is secured at its lower end in a collar 24 mounted in an opening 25 formed in the base member A and secured in such opening by means of screws 26. The spindle 23 has a shoulder 21 formed on an intermediate portion thereof, such shoulder supporting a combination thrust and radial bearing 28 which, in turn. supports a sleeve member 29. The sleeve member 29 is supported-near its upper end by radial bearings 30 engaging the spindle 23 andabove the bearing 39 the sleeve is formed with a hub portion 31 through which a threaded pin 32 extends. the hub portion 3| terminates at its lower end in a shoulder 33 which supports a downwardly extending hub collar 34 formed in the table. This hub collar is keyed to the hub portion 3| of the sleeve as indicated at 35 and is held in proper alignment therewith by means of a washer 36 which is engaged by a nut 31 mounted on the upper threaded end of the pin 32. v

The outer surface of The table C is shown as comprising a plurality of radially extending wing members 38 which are either formed or mounted on the table hub section 34' and the entire unit is provided with a I in the form shown, comprise sleeves which are cast in the wing members and project downwardly relative to the upper faces of such members. The lower ends of the sleeves are provided with bearings indicated at 43. It will be understood, of course, that the construction followed for each of the chucks is the same as that shown in Fig. 3 where the lower end of the chuck member F is shown as being of reduced diameter and is provided with a ,miter gear 44 keyed thereto. 1 r

This miter gear 44 engages a pinion 45 which is mounted on the end of a chuck operating shaft 46 supported by bearings 41 which in turn are secured to the undersurface of the wing member 38. The inner end of the chuck operating shaft 46 is keyed to a pinion 48 which engages a miter gear 49 mounted, through the medium of bolts 50, upon a chuck driving sleeve 5l.- The upper end of the chuck driving sleeve 5| engages a collar 52 which forms a top bearing against ,the table rotating sleeve 29. The lower end of the chuck operating sleeve is mounted upon another bearing collar 53, the inner surface of which engages the table operating sleeve 29 and the lower edge of which rests upon a flange 54 formed on the lower edge of the table operating sleeve.

Reference numeral 56 indicates a main drive gear, and reference numeral 51 indicates a. driving clutch member, both of which are rigidly secured through the medium of pins or bolts 58 to a flange 59 formed on the chuck operating sleeve 5|. This main drive 'gear 56 is engaged by a pinion 60 keyed to the inner end of themain drive shaft D which is shown as being supported at itsinner end by a bearing standard 6| mounted on the base member A.

Reference numeral 62 indicates a clutch plate having a clutch face 63 adapted to engage a corresponding face 64 formed on the lower end of the driving clutch member 51: This clutch plate 62, which is provided with rigid pins 65 extending upwardly into pin recesses 66 formed in the bottom of the table operating sleeve 29, rests upon a bearing 68 mounted in a clutch engaging collar 69 which is adjustably mounted on a nut 69 in threaded engagement with threads 10 formed on the main spindle 23. This collar 69 is adapted to be rotated through the action of the nut 69 on the threads 10 for moving the clutch plate 62 into engagement with the driving clutch member driving member, the table in the meantime having been locked against rotation, the rotation of the main drive shaft D and the consequent rotation of the gear 49 im parts rotation to the chuck driving shafts 46 and their associated parts, in-

cluding the chucks F, the spindles G and the brake drums H supported by the chucks.

When the table is released and the clutch actuating rod II is pulled to the right to rotate the clutch collar 88 in its threads and move the clutch plate 82 into engagement with the driving clutch element 51, the shaft D continuing to rotate drives the clutch plate 82 and consequently through the pins 65 rotates the sleeve 28 to which the table is keyed. At the same time the chuck operating shafts cease to rotate and the table is moved to its next position at which, as pointed out hereinabove, it engages a latch to lock it against further rotation and automatically disengage the clutch which permits the rotation of the shaft D to again be imparted to the chuck operating shafts 38.

In this form of my invention the clutch actuating rod II is pivotally connected, as indicatedat 15, to a clutch actuating lever 18 which is rigidly mounted upon a clutch actuating shaft 11, the shaft 11 being supported in bearings 18 and I8 mounted on the base member A. The lever I8 is continually biased toward a clutch. engaging position by means of a tension spring 19 which, as shown in Fig. 5, is secured to a rigid support 88 on the base member;

The latch mechanism E includes, what I may term, a latch 'member or a lever member 8| (see Figs. 10 and 12) the upper end portion of which engages a stop 82 mounted on the underside ofa table wing. More specifically, the latch member or the lever member 8| comprises a supporting to engage a ball I88 mounted on the upper end bracket 83 which is mounted on the shaft 11, such bracket having projecting cars 88 forming a recess in its upper end-which receives the latch member 8| held therein by means of a pin 85. A second pair of projecting cars 81 form another recess on the bracket member through which the latch member 8| extends and in which such member is heldv by means of a bar or finger 88. The lower end of the latch member 8| is provided with a downwardly extending pin 89 which projects through a notch 98 formed in the lower end of the bracket member and a compression spring 8| encircles the pin 88 and is interposed between a shoulder 92 on the latch member and the foot portion 93 which contains the notch in the bracket. A tension spring 84 is interposed between the lower end of the pin 88, and a projection 95 formed on the lower end of the bracket.

When the latch mechanism is in the position "shown in full lines in Fig. 12, the clutch actu- -ating shaft I1 has been rotated to a position at which the clutch is disengaged and the table is heldv against .further rotation by virtue of the. engagement of the stop member 82 with the notch 85 in the latch member 8|. It will be seen, therefore, that it is necessary -to provide some means for moving the latch member 8| downwardly against the action of the compression spring 8| in order to permit the tension spring I I9 acting upon the lever I6 to rotate the clutch engaging collar for reengaging the table clutch to rotate the table.

V For the purpose of effecting this last mentioned operation, I mount upon the shaft 11 in rotatable relation thereto, a sleeve I88 which has one end in bearing engagement with the bracket member 83 and has mounted upon that end portion thereof a pawl or cam member I8I.' This cam memb er is arranged so as to engage a pin I82 which is mounted on the inside face of the latch member 8|. When the table I has just been stopped from rotation and the clutch disengaged,

the cam is situated with respect to the pin as shown in full lines in Figs. 10, "11, and 12.

In the operation of a trip mechanism of which the cam and sleeve are a part and which will be morev completely described with relation to the mechanism foroperating the'traveiing arm M, the sleeve and the cam are rotated upwardly to'the broken line position shown in Fig. 12 where the flat portion of the-cam nose rests upon or is situated above the pin I82. From the broken line position it will be seen that the next counter clockwise rotation of.the cam and sleeve will be effective to press the latch member 8| downwardly against the action of the compression spring 9| so that itsupper end clears the lower surface of the notch 82' in the stop 82, thereby permitting theclutch actuating shaft TI to be rotated in the counterclockwise direction by the action of the tension spring 18 which will, through the action of the clutch actuating rod 'II, engage the table clutch.

The rotation of the clutch actuating shaft 'Il swings the latch member 8| into the dotted line position shown in Fig. 12 at which position the latch member 8| of itself will not effectively eng'age the stop member. It is, therefore, necessary to provide some means for rotating the latch mechanism and the clutch actuating shaft back to the full line position shown where the latch.

member 8| will engage the next stop on the table. For the purpose of effecting this operation, I

provide an elongated finger cam I88 on the undersurface of the table which is situated so as of the table, engages the ball I84 it swings the lever I85 together with the sleeve in a counterclockwise direction so that a forward face I85 on' the lever or crank I85 engages the end of a screw III! which is adjustably mounted in an .extensionof the bar 88. This movement is indicated in brokenlines shown in Fig. 11. The

continued movement of the finger cam I88, by

virtue of the engagement between the trip lever I85 and the screw II8,swings the bracket and its associated latch -member 8| into the full line position shown in Fig. 12 thereby disengaging the clutch and positioning the latch member 8| for engagement with the. stop 82 on the table. In this' connection it will be seen that the disengagement of the table clutch can be regulated by adjusting the screw II8.

Referring now to Figs. 5 to 9 inclusive for a more complete description of the upright housing 0, the means for actuating the traveling arm, and the remainder of the trip mechanism,

it will be observed that the housing O is provided with a base flange I28.whereby it is secured to the base member A through the medium of screws I2I. "The bottom of the housing and the flange connection are formed so as to provide an oil reservoir I22 in the bottom of the upright housing, the purpose of which will be more fully described later in the specification.

It will be" observed from Fig. 5 that the main drive shaftD which has a bearing 5| on .the base member adiacent the upright housing, extends -of the driving means indicated at P, such sprocket and driving means being encased in a protecting housing I26.

Within the housing 0, the shaft D is provided with a pair of spaced miter pinions I28 and I 29 'rotatably mounted on the shaft. The opposite inner faces I28 and I29 of the pinions are formed with clutch jaws adapted to be engaged by similar clutch jaws I30 and IN formed on the ends of a .clutch collar I32 which is splined to that portion of the shaft D which lies betwe the two pinions I28 and, I29.

The clutch collar I32 is provided .with an annular groove I34 which receives a block I34 slidably mounted between compression springs I35 and upon a curved guide bar I35 which in turn is mounted in a fork I36 formed on the upper end of a lever member I36 which is keyed to a shaft I 42'. The block I34 and its associated mechanism is effective, through opposite rotations of the shaft I42, to move the clutch collar into engagement with the opposite clutch faces on the gears I28 and I 29 and also, under certain operations of the trip mechanism to throw the clutch collar into a neutral position.

The pinions I28 and I29 are in engagement with .a gear I31 which is keyed to the lower end portion of a feed screw I38. The feed screw I38 has its upper end portion 'rotatably mounted in "a bearing I38 which is formed in a bearing bushing I38a mounted in the top of the housing, and the upwardly extending end of the feed screw is provided with a hand wheel I39 for manually operating the same. The lower "end portion 'of the feed screw is supported in a combination radial and thrust hearing I which is contained within a bearing housing MI. The bearing housing I is secured to a bracket member I43 which projects through an opening I44 formed in the housing and which is secured, through medium of screws I45, to a bearing supporting plate I46. This last mentioned plate is mounted upon the face of the housing through-the medium of screws I41 (see Figs. 1 and'l).

For the purpose of properly aligning the lowerbearing I provide shims I49 which are interposed between the plate I46 and the engaged surface of the housing.

The front face of the housing is provided with an elongated opening or way II wherein a feed nut yoke member I52, mounted -,on the back of the arm M as indicated at I53, is adapted to move. The feed nut yoke member I52 extends partially around a feed nut or traveling member I53 which is in threaded engagement with the feed screw,. and is provided with blocks I54 pivotally mounted thereon, such blocks being received in notches I55 formed in the feed nut yoke I52.

On opposite sides of the opening I5I in the housing 0, I provide a pair of undercut plates I51 which are secured thereto by' means of screws I58. The undercut portions of these plates I51 receive inwardly extending projections I59 on gib plates I60, such gib plates being mounted by means of bolts I6I upon the edges of a supporting plate I62 which, in this form of my invention, is cast to the rear end portion of thearm'M.

The top of the plate section I62 is shown as being provided with a shield plate I64 which is,

formed so that it extends at all times over the opening I5I to prevent lubricant being sprayed through the opening onto the machine.

From the construction so far described, it will be seen that as the clutch collar is moved from a neutral position into engagement with the clutch faces on either of the pinions I28 or I29 the feed screw will, through the action of the gear I35, be rotated in opposite directions to move the traveling member I53 and its associated parts including the arm M up or down as the case may be. In this connection it is again pointed out that the main shaft D continues to rotate in the same direction, the operation of the feed screw being controlled solely by the action of the feed screw clutch.

Since the intermittent rotation of the table in the manner described above,and the automatic reversal of the movement of the arm is dependent upon the extent of movement in the arm or the position of the nozzles with respect to the drums, 'it is important that the trip mechanism, which has been partially described hereinabove, include as an element, means which are actuated by the traveling member or some of its associated parts. In this form of my invention, I provide the traveling member or feed nut I53 with an arm or extension I10, the end of which is provided with a collar I1I slidably engaging a' bar or rod "2 which I will hereinafter refer to as a trip bar. This trip bar has its upper end slidably fitted into a cylinder I13 of'a socket member I14 which is secured in an opening in the top of the housing 0 by means of a flange connection I15. The bottom of the trip bar ll2 is secured, through the medium of a stirrup and pin connection I16, to a lever member I11 which is rigidly-secured to the shaft'l42 (see Fig.9).

Mounted on the trip bar I12 at the bottom of the travel of the feed nut I53, is a stop member I80 which supports a compression spring I8I. The compression spring I8I is adapted to be engaged by the collar HI and through such engagement it is compressed against the stop I80 to a point at which the lever I11 ismoved downwardly rotating the shaft I42 in a clockwise direction, and since, under these circumstances the r feed nut is 'moving downwardly, the clutch jaw I30 on the clutch collar I32 is engaged with the corresponding clutch jaw I28 on the gear I28 which rotates the shaft for downward movement of the feed nut, therefore, the clockwise rotation of the shaft I42, through the action of the fork lever I36, disengages the clutch, and the expansion of the compression spring I'8I throws the clutch collar the full width of the gap into engagement with the pinion I29 which reverses the rotation of the feed screw.

For the purpose of limiting the upward movement of the feed nut, I provide the trip bar I12 with another stop member I85, such stop having a projecting handle I06 which extends through her. may be adjusted to control the upward limit of travel of the arm M and its associated parts. Reference numeral I92 indicates a compression spring which is situated on top of the collar member "I and which is adapted to'be compressed between the stop I85 and the collar I1I when thecollar reaches its upper limit of travel.

than the spring I8I so that the action of this spring is merely suflicient to disengage the clutch into engagement with the other gear.

7 extends into the fork 204 in the upper end of v As was pointed out hereinabove, the trip bar:

has, in addition to the functions just' named.

the function of releasing the table latch so as'to permit the engagement of the table clutch when the arrnM reaches its uppermost position. This function is accomplished through the medium of a latch actuating bar 200 which is slidably mounted in bearings 20I and 202 formed in opposite sides of. the housing 0. 1

The bar 200 is provided with a pin 203 which a lever 205 rigidly mounted upon the shaft I42. Various rotative movements of the shaft I42 are, therefore, eiiective, to reciprocate. the bar 200, and for the purpose of stopping and releasably holding the bar; in the three alternative positions which correspond to the up, neutral, "and down positions ofjthe'jclutch coll r. I32, I providethe bar with three .riotche's-indicated. generally by reference numeral) which are adapted to selec-- tively receive" a. s pring pressed ball 208 mounted outlet valve 220 was not large enough to take care collar but will not throw it across the gap and g of this rapid upward movement.

Forthe purpose of mainder. of the oil contained in the cylinder I13,

I provide an auxiliary outlet 221 in the top of the in the bearing member 20I. The bar 200 is connected, through a yieldable spring connection 209, with a rod 2I0 which inturn is secured at its end and through a, yoke 2 to a crank 2I3 rigidly mounted upon the sleeve ,I00 (see Fig. 3).

In addition to forming a part of the trip mechanism, the trip bar I12 comprises part of a novel pump whereby lubricant is continuously supplied to the feed screw and its associated parts during the operation of the machine. As was pointed out above, the upper end of the trip bar I12 is fitted in sliding engagement into the cylinder I13 formed in the socket member. This cylinder is provided at its upper end with a fluid inlet connection 2I5 and a fluid outlet connection 2I8, the inlet connection 2I5 beingconnected through a check valve 2 I1 with an inlet conduit 2I8 which opens at its lower end into the oil reservoir I22.

The fluid outlet connection 2I6 is connected through a check valve 220 with an outlet conduit 22I which opens into a space provided in the top feed screw bearing I38. As the trip rod I12 is moved downwardly through the action of the collar I1I on the stop I80, oil is drawn into the cylinder I13 through the check valve 2" from the oil reservoir. When the collar member "I reaches the upper limit of thestroke and engages the stop member I85, moving the trip rod I12 upwardly, the oil thus received is forced out through the check valve 220 and onto the feed screw I38, across which it is returned to the oil reservoir.

For the purpose ing IlI against grit; or cuttings which may be carried by the oil, I provide a felt ring 225, or a plurality of such rings, in the bearing housing Ill.

As was pointed out-above, the upward movement of the travelingmember or feed nut, gradually moves the trip rod I12 upwardly until the clutch is disengaged. This movement is also efof protecting the bottom bearsocket member I14. This auxiliary outlet is notquickly. releasing the remally closed by a spring pressed check valve 228 which may be adiusted'to give the desired hydraulic cushioning effect to the triprod I12 by means of an adjusting screw .228. Since the movement is imparted to the trip rod directly from the table, it will be seen that this structure provides a hydraulic cushion for the table stop and latch mechanism.

For the purpose of optionally locking the clutch I32 in neutral at the end ofthe downward movement of the feed nut, I provide the trip bar I12 with a neutral locking handle 230 which projects through an opening 23I in a bottom cover plate 232 on the back of the housing 0. Below the extending portion of this lever, I provide a cam plate 233which is pivotally attached to-the cover plate as indicated at 234, such cam plate being provided with a handle 235. When the cam plate 233 is swung into the full line position shown in Fig. 4, it will be engaged by the handle member 230 and will'thereby hold the trip bar I12 against further downward movement beyond the position at-which the feed screw clutch I32 is in neutral.

Referring to Figs. 13 to 16 inclusive, the operation of the trip mechanism, the feed screw clutch, the table latch, and the table clutch is as follows: Referring to Fig. 13 the table member with the finger cam I03 has just been rotated to a position at which the finger cam has passed the ball III, the table having been brought into a position at which the stop 82 is engaged with the latch 85, the table clutch 62 having been disengaged and the' feed screw clutch I32 havin been thrown into engagement with the down" gear I28, thus initiating the rotation of the feed screw in a direction which imparts downward movement to the feed nut I53. It will be observed that in this position the curved nose of the cam IOI rests beneath the pin I02.

As the feed nut I53 travels downwardly, it is. brought into engagement with the stop I as shown in broken lines in Fig. 13, compressing the spring I8 I, thus gradually releasing the clutch collar from the gear I28 against the action of the spring pressed ball 208 in the last notch with which it is in' engagement. When the clutch is released in this manner the latch compression spring I8I is eifective to throw the clutch-collar clear through the neutral position and into'engagement with the up gear I29 to the position as shown inFig. 14.

The movement of the sectional bar 200-210 which accompanies the shift just described, rotates the sleeve I00 so that the nose of the cam IOI passes the pin I02 and assumes a position at which the flat portion .of the cam is situated above or rests upon the pin I02. The feed nut I53 is now moving in an upward direction as indicated in Fig. 14. When the nut reaches its upper limit of travel, as indicated at Fig; 15, the

top spring I92 is compressed against the stop I85, thecontinued upward movement of the REG nut being eifective to move the upright shifter rod I12 upwardly, gradually withdrawing the clutch collar 132 from its engagement with the up gear I29 until it. occupies, a neutral position where the ball 208 is engaged in the central notch 201. This movement of-the sectionalrod 200-2) rotates the flat-face .of the cam I00 downwardly against the pin I02 thus moving the latch 85 into a position at .which it clears the notch in the stop 82. This permits the table clutch actuating shaft H to be rotated by the action of the tension spring 19 in a clutch engaging direction which engages the table clutch, thereby initiating the rotation of the table.

Fig. 15 shows the clutch as having been engaged and illustrates the next cam and stop'on the table as being in a position just prior to the engagement of the cam I03 with the ball H14 on the sleeve supported lever M5. The continued movement of the table rotates the lever rearwardly into the position shown in Fig. 16 at which the latch member 85 is swung up into a position at which it will be engaged by the stop member 82. This movement also disengages the clutch and swings the segmental bar 2002l0 forwardly into the position in Fig. 13, also engaging the feed screw clutch with the down gear I28 and giving a final upward thrust to the i Fig. 18.

'T-head K is adjusted so that the spray will just strike the rim of the drum, and the, downward movement imparted to the nozzles from the feed screwis so related to-the rotation of the drum that the nozzles are moved, say, one-third the width of the area covered by the spray for each rotation of the drum. This results in an overlapping series of layers which forms the mat of hard metal on the inner surface of the drum, such layers being indicated at Ll, L2, and L3 in As the nozzles traverse their upward course, another series of layers are laid on the wearing surface so that the surface (in the event the relative movement between the nozzle and the drum is as pointed out above) will be made 'up of six thicknesses of metaL- It will be understood of course that each drum may be given as many applications as desired to obtain the re-,

quired thickness, but the operation of the machine is such that the deposited metal is permitted to set after each depositing operation, but not to harden to an extent preventing secure bonding together, of the successive spray-deposited layers.

It will be seen from the foregoing description that when the table has stopped in a position for spraying one set of drums, the othe set of drums is free to be removedand replaced with an untreated or unlined set. The operation of the machine is entirely automatic and the only manual operations are those just mentioned in connection with the drums.

It is again emphasized that the method and apparatus contemplated by this invention is not confined to use in'repairing worn or scored drums, but that it may be used in placing upon a new drum, a wearingsurface having greater hardness and durability and ahigher coefficient of friction than can be obtained in an original forging or casting.

. gear, for rotating said table; means for'releasing said table and engaging said eludes within its scope whatever changes fairly come within the spirit of the appended claims.

I claim as my invention:

1. A machine for applying a metal coating to brake drums and the like embodying: a table; means for rotatably supporting said table; means on said table for supporting a plurality of drums;- means including a main gear for rotating said drum supporting means, said main gear being coaxial with the table support; a metal spray gun; means for supporting said spray gun above said table; means for effecting relative up and down movement between a drum engaged by said drum supporting means and said spray gun; latch means for normally holding said table in a fixed position relative to said spray gun; means including a clutch, which is coaxial with the table support and is adapted to be driven by said main and automatic table rotating clutch when a predetermined position of saidspray gun relative to said drum has been reached.

2. A machine for applying a metal coating to brake drums and the like embodying: a table; means for rotatably supporting said table; means on said table for supporting a plurality of drums; means, including a main gear coaxial with said table support, for rotating said drum supporting means; a metal spray gun; means for supporting said spray gun above said table; means for effecting relative up and down movement between a drum engaged by said drum supporting means and said spray gun; latch means for normally holding said table in a fixed position relative to said spray gun; means including a clutch, which is coaxial with the table supporting means and is adapted to be driven by said main gear, for rotating said table; automatic means for releasing said table and engaging said table rotating clutch when a predetermined position of said spray gun relative to said drum has been reached; and means on said table for engaging said latch to lock said table against further rotation when it has been rotated to a predetermined position relative to said spray gun.

3. A machine for applying a metal coating to brake drums and the like embodying: a table; means for rotatably supporting said table; means on said table for supporting a plurality of drums;

means including a main gear for rotating said drum supporting means; a metal spray gun; means for supporting said spray gun above said table; means for effecting relative up and down movement between a drum engaged by said drum supporting means and said spray gun; latch means for normally holding said table in a fixed position relative to said spray gun; means including a clutch element formed integrally with said main gear for rotating said table; automatic means for releasing said table and engaging said table rotating clutch when a predetermined position of said spray gun relative to said drum has been reached; and means operableby said automatic means for disengaging said means which eiTect the up and down movement between said spray gun and said drum.

4. A machine for applying metal coating to brake drums and the like embodying: a table; means for rotatably supporting said table; means on said table for supporting a plurality of drums; means including a main gear for rotating said drum supporting means; a metal'spray gun; means forsupporting said spray gun above said table; means for effecting relative up and down said mainlgear for rotating said table; automatic means for releasing said table latch and engaging said table rotating clutch when a predetermined position of said spray gun relative to said drum has been reached; means operable by said automatic means for disengaging said means a which efiect the up and down movement between said spray gun and said drum, means on said table for engaging said latch to lock said table against further rotation when it has been rotated toa predetermined position relative to said spray gun; and means operable by said latch for reengaging the means which efiect said up and down movement between the spray gun and the drum 5. A machine for applying a metal coating to brake drums and the like embodying: a table; means for rotatably supporting said table; means including a main gear and a clutch for rotating said table, said main gear and clutch being coaxial with respect to the table-supporting means; means for supporting a plurality of drums on said table; means actuated by said main gear when said table is stationary for rotating said drums; a metal spray gun; means for supporting said spray gun above said table; means for moving said spray gun support downwardly toward said table; 'and automatic means operable when said spray gun support has reached a predetermined downward position to reverse the direction of movement of said spray gun support.

7.6. A machine for applying a metal coating to brake drums and the like embodyin a table;

means for rotatably supporting said table; means including a main gear and a clutch for rotating said table, said main gear and clutch being coaxial with respect to the table-supporting means; means for supporting a plurality of drums on said table; means actuated by said main gear when said table is stationary for rotating said drums; a metal spray gun; means for supporting said spray gun above said table; latch means for locking said table with one of said drums in a predetermined position relative to said spray gun; means for moving said spray gun support downwardly toward said table; automatic means operable when said spray gun support has reached a predetermined'position to reverse the direction of said spray gun support moving means; and automatic means operable when said spray gun support has reached a predetermined upward position to disengage said spray gun support moving means.

'L- A machine for applying a metal coating to brake-drums and the like embodying: a table; meansfor rotatably'supporting said table; means including a main gear and a clutch for rotating said table, said main gear and clutch being coaxial; with respect to the table-supporting means; means .for supporting a plurality of drums on said table; means actuated by said main gear when said clutch is disengaged for rotating said drums; a metal spray gun; means for supporting said spray gun above said table; latch direction of said spray gun support moving means; automatic means operable when said spray gun support has reacheda predetermined upward position to disengage said spray gun support moving means; and means operable by said last mentioned automatic means for releasing said table-holding latch and engaging said table rotating clutch.

8. A machine for applying a metal coating to brake drums and the like embodying: a table; means for rotatably supporting said table; means including a main gear and a clutch for rotating said table, said main gear and-clutch being coaxial with respect to the table-supporting means; means Ior supporting a plurality ofdrums on said table; means engaging said main gear for rotating said drums when said clutch is disengaged; a metal spray gun; means for supporting said spray gun above said table; latch means for means for moving said spray gun support downwardly toward said table; automatic means operable when said spray gun support has reached a predetermined position to reverse the direction of said spray gun support moving means; automatic means operable when said spray gun support has reached a predetermined upward position to disengage said spray gun support moving means; means operable by said last mentioned automatic means for releasing said table holding latch and engaging said table rotating clutch; and stop means on said table for engaging said latch to hold said table against further rotation when it reaches a predetermined position relative to'said spray gun.

9. A machine for applying a metal coating to brake drums and the like embodying: a table; means for rotatably supporting said table; means including a main gear and a clutch for rotating said table, said main gear and clutch being coaxial with respect to the table-supporting means; means for supporting a plurality of drums on said table; means engaging said main gear for rotating said drum; a metal spray gun; means for supporting said spray gun above said table; latch means for locking said table with one of said drums in a predetermined position relative to said spray gun; means for moving said spray gun support downwardly toward said table;

automatic means operable when said spray gun able when said spray gun support has reached a predetermined upward position to disengage said spray gun" support moving means; means operable by said last mentioned automatic means .for releasing said table holding latch and engaging said table rotating clutch; stop clutch on said table for engaging said latch to .hold said table against further rotation when it reaches a predetermined position. relative to said spray gun; and means operable by said latch'when engaged by said stop means for disengaging said table rotating means and reengaging said downwardly operating spray gun support moving means.

10. A machine for applying a metal coating to brake drums and the like embodying: a table; means for rotatably supporting said table; means including a main gear and a clutch for rotating said table, said main gear and clutch being coaxial with respect to the table-supporting means; means for supporting a plurality of drums on said table; means engaging said main gear for rotating said drums; a metal spray gun; adjustable means for supporting said'spray gun above said table; meansfor moving said spray gun support downwardly toward said table; and automatic means operable when said spray gun support'has reached a predetermined downward po-' sition to reverse the direction of movement of said spray gun support.

11. A machine for applyinga metal coating to brake drums and the like embodying: a table; means for rotatably supporting said table; means including a main gear and a clutch for rotating said table; means for supporting a plurality of drums on said table; means engaging said main gear for rotating said drums when said clutch is disengaged; a metal spray gun; adjustable means for supporting said spray gun above said table;

latch means for locking said table with one of j said drums in a predetermined position relative to said spray gun; means for moving said spray gun support downwardly toward said table automatic means operable when said spray gun sup port has reached a predetermined position to reverse the direction of said spray gun support moving means; and automatic means including an adjustable stop operable when said spray gun support has reached a predetermined upward. po-

sition to disengage said spray gun support moving means.

12. A machine for applying a metal coating to brake drums and the like embodying: a table;

means for rotatably supporting said table; means for rotatably supporting 'a plurality of brake drums on said table; a main drive shaft; means including a maingear, coaxial with the tablesupporting means, for rotating said drum supports from said main drive shaft; means including a table clutch associated with said gear for rotating said table from said main drive shaft, said table clutch being coaxial with the table- .supporting'means; an upright housing arranged in offset relation with the axis of said table;

' guide means on said housings; a spray gun supporting arm slidably mounted on said guide -means; a spray gun mounted on said armabove said table; means including an upright feed screw in said housing for moving said arm; and means including a-olutch on said main drive shaft for rotating said feed screw inopposite directions.

13., A machine for applying a metal coating to brake drums and the like embodying: a base member; a table; means on said base member for rotatably supporting said table; means for rotatably supporting a plurality of brake drums on said table; a main drive shaft; means including a main gear coaxial with said table-supporting means for rotating said drum supports from said main drive shaft; means including a table clutch coaxial with said table-supporting means for rotating said table from said main drive shaft; an upright .housing mounted on said base member in} offset relation with said table; guide means on said housing; a spray gun supporting arm slidably mounted on said guide means; a metal spray 14. A machine for applying a metal coating to brake drums and the like embodying; a base member; a table; means on said base member for rotatably supporting said table; means for rotatably supporting a plurality of brake drumson said table; a main drive shaft; means including a main gear coaxial with said table-supporting'means for rotating said drum supports from said main drive shaft; means including a table clutch coaxial with said table-supporting means for rotating said table from said main drive shaft; an upright housing mounted on said base member in offset relation with said table; guide means on said housing; a spray gun supporting arm slidably mounted on said guide means; a metal spray gun mounted on said arm above said table; an upright feed screw in said housing; means including a clutch member on said main drive shaft for driving said feed screw in oppo site directions; means including a traveling member on said feed screw for imparting up and down movement to said arm; an upright shifter rod reciprocably mounted in said housing; stops on said shifter rod adapted to be engaged by said traveling member; and means at the lower end of said shifter rod for throwing said :feed screw clutch.

15.- A machine for spraying brake drums and the like embodying: a table; means for rotatably supporting said table; means for rotatably supporting a plurality of brake drums on said table; a main drive shaft; means for rotating said drum supports from said main "drive shaft; means including a table clutch for rotating said table from said main drive shaft; an upright housing; guide means on said housing; a spray gun supporting arm slidably mounted on said guide means; a spray gun mounted on said arm above said table; an upright feed screw in said housing; means including a clutch member on said main drive shaft for driving said feed screw in opposite directions; means including a traveling member on said feed screw for imparting up and down movement to said arm; a socket in the top of said housing; an upright shifter rod having its upper end portion reciprocably mounted in said socket; an inlet port .and an outlet port in the top of said socket; valves in said ports; a conduit leading from said inlet port to an oil reservoir in the bottom of said housing; a dis-' charge conduit imsaid outlet port having'a'n outlet adjacent said feed screw; stops on saidshifter rod adapted to be engaged by said traveling member for reciprocating said rod; and means at the lower end of said rod for throwing said feed screw clutch.

16. A machine for applying a metal coating to brake drums and the like embodying: a base memher: a table; means on said base member for rotatably supporting said table; means for rotatably supporting a plurality of brake drums on said table; a main drive shaft; means including a main gear coaxial with the table-supporting means for rotating said drum supports from-said main drive shaft; means including a table clutch coaxial-with the table-supporting means for rotating said tablefrom said main drive shaft; an upright housing mounted on said base member in offset relation with said table; guide means on said housing; a spray gun supporting arm slidably mounted on said guide means; a metal spray gun mounted on said arm. above said-table; a feed screw bearing in the top of said housing; a feed screw having its upper end mounted in said bearing; a bottom feed screw bearing adjustably mounted in the bottom of said housing; a traveling member on said feed screw for moving said arm in said guide; and means including a clutch member on said main drive shaft for rotating said feed screw in opposite directions.

17. A machine for applying a metal coating to brake drums and the like embodying a base member; a table; means on said base member for rotatably supporting said table; means for rotatably supporting a plurality of brake drums on said table; .a main drive shaft; means including a main gear coaxial with the table supporting means for rotating said drum supports from said main drive shaft; means including a table clutch coaxial with the table-supporting means forrotating said table from said main drive shaft; an upright housing mounted on said base member in offset relation with said table; guide means on said housing; a spray gun supporting arm slid- .ably mounted on said guide means; a metal spray gun mounted on said arm above said table; means including an upright feed screw in said housing for moving said arm; means including a clutch on said main drive shaft for rotating said feed in opposite directions; and adjustable means for locking said clutch in a neutral position.

18. In a device of the class described: a table; means for supporting work on said table; means for rotatably supporting said table; means including .a clutch and a main gear, both coaxial with said table-supporting means for rotating said table; a main drive shaft for driving said main gear and, table clutch; a table clutch operating shaft; means on said table clutch operating shaft for actuating said table clutch; yieldable means for moving said table clutch actuating means to engage said table clutch; a latch member on said clutch operating shaft; a stop on said table adapted to engage said latch and hold said table clutch in disengagement against the action of said yieldable means; and means for releasing said latch means from said stop to permit the engagement of said clutch by said yieldable means.

19. In a device of the class described: a rotatable work-supporting table; a support for said table; means including a main gear and a clutch both coaxial with the table support for rotating said table; a horizontal main drive shaft for driving said table clutch; bearing ,means supporting said main drive shaft; an upright guide member adjacent said table in ofi'set relation therewith; a traveling arm having a portion thereof engaged in said guide member and an extending portion projecting above said table; an upright feed screw mounted adjacent said guide member; bearing means supporting said feed screw; a traveling member on said feed screw; means engaged by said traveling member for moving said arm; means including a reversing clutch on said main drive shaft for rotating said feed screwin opposite directions; and trip means adapted to be engaged by said traveling member for throwing said feed screw clutch.

20. In a device of the class described: a rotatable work supporting table; a support for said table, means including a main gear and a clutch both coaxial with the table-supporting means for rotating said table; a main drive shaft for driving said table clutch; bearing means supporting said main drive shaft; an upright guide member adjacent said table in offset relation therewith; a traveling arm having a portion thereof engaged in said Tuide member and an extending portion projecting above said table; an upright feed screw mounted adjacent-said guide member; bearing means supporting said feed screw; a traveling member on said feed screw; means engaged by said traveling member for moving said arm; means including a reversing clutch on said main drive shaft forrotating said feed screw in opposite directions; means including a yieldable member for engaging said table clutch; latch means actuated by said table for holding said table clutch in disengagement against the action of said yieldable means; trip means adapted to be engaged by said'traveling member for releasing said latch to permit the rotation of said table and the engagement of said clutch; and means operable by said latch means for disengaging said feed screw clutch. V

21. In a device of the class described: a rotatable work supporting table; a support for said table, means including a main gear and a clutch both coaxial with the table-supporting means for rotating said table; a main drive shaft for driving said table clutch; bearing means supporting said main drive shaft; an upright guide member adjacent said table in offset relation therewith; a traveling arm having a portion thereof engaged in said guide member and an extending portion projecting above said table; an upright feed screw mounted adjacent said guide member; bearing means supporting said feed screw; a traveling member on said feed screw; means engaged by said traveling member for moving said arm; means including a reversing clutch on said main drive shaft for rotating said feed screw in opposite directions; means including a yieldable member for engaging said table clutch; latch means actuated by said table for holding said table clutch in disengagement against the action of said yieldable means; trip means adapted to be engaged by said traveling member for releasing said latch to permit the rotation of said table and the engagement of said clutch; means operable by said latch means for disengaging said feed screw clutch; and means including a cam member on said table and a lever member in said trip mechanism engageable therewith after a predetermined rotation of said table for disengaging said table clutch and reengaging said feed screw clutch.

22. In a device of the class described: a rotatable work supporting table; a support for said table, means including a main gear and a clutch both coaxial with the table-supporting means for rotating said table; a main drive shaft for driving said table clutch; bearing means supporting said main drive shaft; an upright guide member ad- .jacent said table in offset relation therewith; a

member at the bottom of its movement for throwing said feed screw clutch to reverse the rotation of said feed screw.

23. In a device of the class described: a work supporting table; means including a clutch for rotating said table; a main drive shaft for driving said table clutch; bearing means supporting said main drive shaft; an upright guide member adjacent said table; a traveling arm having a portion thereof engaged in said guide member and an extending portion projecting above said table; an upright feed screw mounted adjacent said guide member; bearing means supporting said feed screw; a traveling member on said feed screw; means engaged by said traveling member for moving said arm; means including a reversing clutch on said main drive shaft for rotating said feed screw in opposite directions; means includ-- ing a yieldable member for engaging said table clutch; latch means associated with said table for holding said table clutch in disengagement against the action of said yieldable means; a trip bar adjacent said feed screw; a stop on said trip bar engageable by said traveling member at the bottom of its movement; means operable by the downward movement of said trip bar to throw said feed screw clutchinto a reverse position; another stop on said trip bar engageable by said traveling member at the top of its stroke; and means operable by the upward movement of said trip bar to disengage said feed screw clutch and release said latch, thereby permitting the engagement of said table clutch and the rotation of said table.

24. In a device of the class described: a work supporting table; means including aclutch for rotating said table; a main drive shaft for driving said table clutch; bearing means supporting said main drive shaft; an upright guide member adjacent said table; a traveling arm having a por: tion thereof engaged in said guide member and an extending portion projecting above said table; an upright feed screw mounted adjacent said guide member; bearing means supporting said feed screw; a traveling member on said feed screw; means engaged by said traveling member for moving said arm; means including a reversing clutch on said main drive shaft for rotating said feed screw in opposite directions; means including a yieldable member for engaging said table clutch; latch means associated with said table for holding said table clutch in disengagement against the action of said yieldable means; a trip bar adjacent said feed screw; a stop on said trip bar engageable by said traveling member at the bottom of its movement; means operable by the downward movement of said trip bar to throw said feed screw clutch into a reverse position; another stop on said trip bar engageable by said traveling member at the top of its stroke;

means operable by the upward movement of said trip bar to disengage said feed screw clutch and release said latch, thereby permitting the engagement of said table clutch and the rotation of said table; and means including a cam member on said table and a lever member in said trip mecha'- nism for disengaging said table clutch and reengaging said feed screw clutch.

25. The i- :thod of treating brake drums and the like, which includes: subjecting the wearing surface thereof to the action of a hot metal spray; rotating said drum during such spraying action; and effecting a gradual reciprocating axial movement between said drum and said spray during the rotation of said drum so as to build up a matted hard metal coating in said drum.

26. The method of treating a brake-drum which comprises subjecting thewearing surface thereof to the action of a spray of molten metal PURLING A. BLEAKLEY. 

